The concept of applying cue indicia to one or both side edges of a recordable web such as magnetic tape to facilitate the location of audio pause intervals between recorded selections was introduced by commonly owned, copending application Ser. No. 199,475 filed Nov. 17, 1971now U.S. Pat. No. 3,810,246 and reference may be had thereto for a full statement of the advantages inhering from the use of edge marked tapes.
The method heretofore employed for edge marking tape is substantially the same as that disclosed in the aforesaid copending application and involves the intermittent movement of an inked marking roller into marking contact with the tape edge. The primary disadvantage in that method is a function of the ink drying time. Thus, following marking of the tape the ink must be dried before winding onto a take-up reel to avoid ink smear onto adjacent unmarked portions of the tape. This requires substantial transport of the tape prior to take-up as to permit of air drying, passage through a drying oven, etc. Such tape transport, in turn, requires specially designed idle pulleys to avoid ink smear onto the guide flange of a conventional idle pulley. An ancillary disadvantage is the precise adjustment that must be maintained between the inking roller and running tape edge. If the roller approaches too closely ink will be deposited on the record surface of the tape while a less than precise approach fails to mark the tape. In the latter event, because of the desired high speed transport onto a take-up reel, the failure to mark is not noticeable until after the tape is wound on the take-up reel which results in loss of the entire reel.
The supply and take-up reels previously referred to may, in the case of magnetic tape destined for use in cassettes, typically accommodate 6,000 feet of tape. In the case of prerecorded tapes, the blank tape is supplied by the manufacturer in the form of a "pancake" which may comprise the 6,000 foot supply reel. The supply reel is threaded onto a take-up reel for high speed transport therebetween across a record head in a so-called duplicating operation wherein a master tape recording is duplicated a plurality of times along the length of the tape as it is transported to the take-up reel. Following duplication, the take-up reel becomes the supply reel for a cassette loading machine of conventional design. When cassettes are to be loaded with non-recorded tape which is not edge marked, the original supply reel from the manufacturer becomes the supply reel for the cassette loading machine.
The primary object of the invention is to permit high speed marking of virtually any tape length in a manner rendering the practice of the invention insensitive to ink drying time and wherein the freshly applied ink does not come into contact with any moving parts. The foregoing is achieved by the simultaneous application of the required cue marks to a side edge of the magnetic tape while it is in the wound condition.